Gengrid¶

Widget description¶
This widget aims to position objects in a grid layout while actually
creating and rendering only the visible ones, using the same idea as the
Genlist
: the user defines a class for
each item, specifying functions that will be called at object creation,
deletion, etc. When those items are selected by the user, a callback
function is issued. Users may interact with a gengrid via the mouse (by
clicking on items to select them and clicking on the grid’s viewport and
swiping to pan the whole view) or via the keyboard, navigating through
item with the arrow keys.
Scrollable Interface¶
This widget supports the scrollable interface.
If you wish to control the scolling behaviour using these functions,
inherit both the widget class and the
Scrollable
class
using multiple inheritance, for example:
class ScrollableGenlist(Genlist, Scrollable):
def __init__(self, canvas, *args, **kwargs):
Genlist.__init__(self, canvas)
Gengrid layouts¶
Gengrid may layout its items in one of two possible layouts:
horizontal or
vertical.
When in “horizontal mode”, items will be placed in columns, from top to bottom and, when the space for a column is filled, another one is started on the right, thus expanding the grid horizontally, making for horizontal scrolling. When in “vertical mode” , though, items will be placed in rows, from left to right and, when the space for a row is filled, another one is started below, thus expanding the grid vertically (and making for vertical scrolling).
Gengrid items¶
An item in a gengrid can have 0 or more texts (they can be regular text
or textblock Evas objects - that’s up to the style to determine), 0 or
more contents (which are simply objects swallowed into the gengrid
item’s theming Edje object) and 0 or more boolean states, which
have the behavior left to the user to define. The Edje part names for
each of these properties will be looked up, in the theme file for the
gengrid, under the Edje (string) data items named "texts"
,
"contents"
and "states"
, respectively. For each of those
properties, if more than one part is provided, they must have names
listed separated by spaces in the data fields. For the default gengrid
item theme, we have one text part ("elm.text"
), two content
parts ("elm.swalllow.icon"
and "elm.swallow.end"
) and no
state parts.
A gengrid item may be at one of several styles. Elementary provides one
by default - “default”, but this can be extended by system or
application custom themes/overlays/extensions (see
Theme
for more details).
Gengrid item classes¶
In order to have the ability to add and delete items on the fly, gengrid
implements a class (callback) system where the application provides a
structure with information about that type of item (gengrid may contain
multiple different items with different classes, states and styles).
Gengrid will call the functions in this struct (methods) when an item is
“realized” (i.e., created dynamically, while the user is scrolling the
grid). All objects will simply be deleted when no longer needed with
delete()
. The GengridItemClass
class contains the
following attributes and methods:
item_style
- This is a constant string and simply defines the name of the item style. It must be specified and the default should bedefault
.func.text_get
- This function is called when an item object is actually created. Thedata
parameter will point to the same data passed toitem_append()
and related item creation functions. Theobj
parameter is the gengrid object itself, while thepart
one is the name string of one of the existing text parts in the Edje group implementing the item’s theme. SeeGengridItemClass.text_get()
.func.content_get
- This function is called when an item object is actually created. Thedata
parameter will point to the same data passed toGengridItem.append_to()
and related item creation functions. Theobj
parameter is the gengrid object itself, while thepart
one is the name string of one of the existing (content) swallow parts in the Edje group implementing the item’s theme. It must returnNone,
when no content is desired, or a valid object handle, otherwise. The object will be deleted by the gengrid on its deletion or when the item is “unrealized”. SeeGengridItemClass.content_get()
.func.state_get
- This function is called when an item object is actually created. Thedata
parameter will point to the same data passed toGengridItem.append_to()
and related item creation functions. Theobj
parameter is the gengrid object itself, while thepart
one is the name string of one of the state parts in the Edje group implementing the item’s theme. ReturnFalse
for false/off orTrue
for true/on. Gengrids will emit a signal to its theming Edje object with"elm,state,xxx,active"
and"elm"
as “emission” and “source” arguments, respectively, when the state is true (the default is false), wherexxx
is the name of the (state) part. SeeGengridItemClass.state_get()
.func.del
- This is called whenefl.elementary.object_item.ObjectItem.delete()
is called on an item orclear()
is called on the gengrid. This is intended for use when gengrid items are deleted, so any data attached to the item (e.g. its data parameter on creation) can be deleted. SeeGengridItemClass.delete()
.
Usage hints¶
If the user wants to have multiple items selected at the same time,
multi_select
will permit it. If the gengrid is
single-selection only (the default), then selected_item
will return the selected item or None
, if none is selected. If the
gengrid is under multi-selection, then selected_items
will return a list (that is only valid as long as no items are modified
(added, deleted, selected or unselected) of child items on a gengrid.
If an item changes (internal (boolean) state, text or content changes),
then use update()
to have gengrid update the item with
the new state. A gengrid will re-“realize” the item, thus calling the
functions in the GengridItemClass
set for that item.
To programmatically (un)select an item or get the selected state, use
GengridItem.selected
. To make an item disabled (unable to be
selected and appear differently) or get the disabled state
use GengridItem.disabled
.
Grid cells will only have their selection smart callbacks called when
firstly getting selected. Any further clicks will do nothing, unless you
enable the “always select mode”, with select_mode
as
ELM_OBJECT_SELECT_MODE_ALWAYS
, thus making every click to issue
selection callbacks. select_mode
as
ELM_OBJECT_SELECT_MODE_NONE
will turn off the ability to select items
entirely in the widget and they will neither appear selected nor call
the selection smart callbacks.
Remember that you can create new styles and add your own theme
augmentation per application with
Theme.extension_add
. If you
absolutely must have a specific style that overrides any theme the user
or system sets up you can use
Theme.extension_add
to add such
a file.
Emitted signals¶
activated
- The user has double-clicked or pressed (enter|return|spacebar) on an item. Theevent_info
parameter is the gengrid item that was activated.clicked,double
- The user has double-clicked an item. Theevent_info
parameter is the gengrid item that was double-clicked.clicked,right
- The user has right-clicked an item. Theevent_info
parameter is the item that was right-clicked. (since: 1.13)longpressed
- This is called when the item is pressed for a certain amount of time. By default it’s 1 second.selected
- The user has made an item selected. Theevent_info
parameter is the gengrid item that was selected.unselected
- The user has made an item unselected. Theevent_info
parameter is the gengrid item that was unselected.realized
- This is called when the item in the gengrid has its implementing Evas object instantiated, de facto.event_info
is the gengrid item that was created.unrealized
- This is called when the implementing Evas object for this item is deleted.event_info
is the gengrid item that was deleted.changed
- Called when an item is added, removed, resized or moved and when the gengrid is resized or gets “horizontal” property changes.scroll,anim,start
- This is called when scrolling animation has started.scroll,anim,stop
- This is called when scrolling animation has stopped.drag,start,up
- Called when the item in the gengrid has been dragged (not scrolled) up.drag,start,down
- Called when the item in the gengrid has been dragged (not scrolled) down.drag,start,left
- Called when the item in the gengrid has been dragged (not scrolled) left.drag,start,right
- Called when the item in the gengrid has been dragged (not scrolled) right.drag,stop
- Called when the item in the gengrid has stopped being dragged.drag
- Called when the item in the gengrid is being dragged.scroll
- called when the content has been scrolled (moved).scroll,drag,start
- called when dragging the content has started.scroll,drag,stop
- called when dragging the content has stopped.edge,top
- This is called when the gengrid is scrolled until the top edge.edge,bottom
- This is called when the gengrid is scrolled until the bottom edge.edge,left
- This is called when the gengrid is scrolled until the left edge.edge,right
- This is called when the gengrid is scrolled until the right edge.moved
- This is called when a gengrid item is moved by a user interaction in a reorder mode. Theevent_info
parameter is the item that was moved.index,update
- This is called when a gengrid item index is changed. Note that this callback is called while each item is being realized.highlighted
- an item in the list is highlighted. This is called when the user presses an item or keyboard selection is done so the item is physically highlighted. Theevent_info
parameter is the item that was highlighted.unhighlighted
- an item in the list is unhighlighted. This is called when the user releases an item or keyboard selection is moved so the item is physically unhighlighted. Theevent_info
parameter is the item that was unhighlighted.item,focused
- When the gengrid item has received focus. (since 1.10)item,unfocused
- When the gengrid item has lost focus. (since 1.10)item,reorder,anim,start
- This is called when a gengrid item movement has just started by keys in reorder mode. The parameter is the item that is going to move. (since 1.10)item,reorder,anim,stop
- This is called when a gengrid item movement just stopped in reorder mode. The parameter is the item that was moved. (since 1.10)
Enumerations¶
Items’ scroll to types¶
- efl.elementary.ELM_GENGRID_ITEM_SCROLLTO_NONE¶
No scroll to
- efl.elementary.ELM_GENGRID_ITEM_SCROLLTO_IN¶
Scroll to the nearest viewport
- efl.elementary.ELM_GENGRID_ITEM_SCROLLTO_TOP¶
Scroll to the top of viewport
- efl.elementary.ELM_GENGRID_ITEM_SCROLLTO_MIDDLE¶
Scroll to the middle of viewport
- efl.elementary.ELM_GENGRID_ITEM_SCROLLTO_BOTTOM¶
Scroll to the bottom of viewport
Added in version 1.17.
Multi-select mode¶
- efl.elementary.ELM_OBJECT_MULTI_SELECT_MODE_DEFAULT¶
Default multiple select mode
Added in version 1.10.
- efl.elementary.ELM_OBJECT_MULTI_SELECT_MODE_WITH_CONTROL¶
Disallow mutiple selection when clicked without control key pressed
Added in version 1.10.
- efl.elementary.ELM_OBJECT_MULTI_SELECT_MODE_MAX¶
Value unknown
Added in version 1.10.
Reorder type¶
- efl.elementary.ELM_GENGRID_REORDER_TYPE_NORMAL¶
Normal reorder mode
Added in version 1.11.
- efl.elementary.ELM_GENGRID_REORDER_TYPE_SWAP¶
Swap reorder mode
Added in version 1.11.